BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Astrophysical signatures on the LISA data stream from Massive Blac
 k Hole Binaries - Mudit Garg (University of Zurich)
DTSTART:20240223T130000Z
DTEND:20240223T140000Z
UID:TALK212428@talks.cam.ac.uk
CONTACT:Xi Tong
DESCRIPTION: European Space Agency recently adopted the Laser interferomet
 ry space antenna (LISA) to launch it in the 2030s to observe Gravitational
  waves (GWs) in the millihz frequency band. LISA's primary sources are mas
 sive black hole binaries (MBHBs) of 10^4-10^8 solar masses due to the merg
 er of galaxies\, stellar-mass BHs coalescence into their galactic central 
 MBH\, and numerous white dwarf binaries that exist in the Milky Way. I foc
 us on MBHBs that usually require an environment consisting mainly of gas a
 nd stars to merge within the Universe's lifetime. I primarily consider the
  effects of a gas accretion disc for a sub-pc separation as it can signifi
 cantly torque the binary to affect the initial binary parameters in the LI
 SA band\, especially orbital eccentricity. While gas perturbations become 
 sub-dominant to GWs a few years before the merger of MBHBs\, they can stil
 l cause detectable phase shifts and excite observable eccentricities for r
 easonable disc properties that hint toward their history before reaching t
 he millihz band. I will use analytical and numerical techniques to show th
 e minimum measurable eccentricity of an MBHB that LISA will measure in a v
 acuum and gas. To be robust\, I consider a high-order post-Newtonian gravi
 tational waveform model\, LISA's motion in its orbit around the Sun\, and 
 the time delay interferometery to enhance astrophysical signal over the do
 minant laser noise. I also explore if a weak gas effect can be mimicked by
  a small eccentricity and vice versa to motivate synergies between LISA an
 d electromagnetic observations to unlock mysteries of the MBHB evolution.
LOCATION:Potter room/Zoom
END:VEVENT
END:VCALENDAR